Time-detecting system for a digital interval timer

ABSTRACT

A time-detecting system for a digital interval timer comprises a plurality of detecting wheels mounted for rotation independently of each other upon a detection shaft. The time-indicating wheels of the timer are also mounted for rotation independently of each other upon the detection shaft and each timing wheel is positioned on the shaft adjacent one of the detecting wheels. Each detecting wheel includes a set of projections which extend toward its associated timing wheel and each timing wheel has a corresponding set of holes for receiving therein the projections when the detecting wheels and timing wheels are angularly aligned with respect to each other. A biasing spring urges the detection shaft in one direction to force the detecting wheels against their associated timing wheels so that when the projections and holes on each set of wheels are in alignment, the biasing spring will force the detection shaft in one direction causing the projections to slide into their respective holes. The movement of the detection shaft thus provides an output indicating that the reference time set in the timer coincides with the actual time displayed by the time-indicating wheels.

IJriited States Patent IIH lfiltai et al.

1 Oct. 2, 1973 1 TIME-DETECTING SYSTEM FOR A DIGITAL INTERVAL TIMER [75] Inventors: Kiyoshi Kitai, Tokyo; Mitsuo Koyama, Chiba-ken; Shogo Kato, Kichioka; Yuzuru Takazawa, Tokyo; Shinji Nagaoka, Chiba-ken, all of Japan [73] Assignee: Seiko Koki Kabushiki Kaisha,

Tokyo, Japan 221 Filed: Nov. 20, 1972 [21] Appl. No.: 307,865

[30] Foreign Application Priority Data Nov. 18, 1971 Japan 46/091886 [52] 11.5. CI. 58/22, 58/20 [51] lnt. Cl. G04b 13/00 [58] lField of Search 58/19, 20, 22, 22.5, 58/38 [56] References Cited UNITED STATES PATENTS 460,751 10/1891 Madel 58/22 2,701,439 2/1955 Junghans et al. 58/22 3,685,280 8/1972 Fehrenbacher 58/22.5 X

Primary Examiner-Richard B. Wilkinson Assistant Examiner-Lawrence R. Franklin Alt0rney-Robert E. Burns et al.

[57] ABSTRACT A time-detecting system for a digital interval timer comprises a plurality of detecting wheels mounted for rotation independently of each other upon a detection shaft. The time-indicating wheels of the timer are also mounted for rotation independently of each other upon the detection shaft and each timing wheel is positioned on the shaft adjacent one of the detecting wheels. Each detecting wheel includes a set of projections which extend toward its associated timing wheel and each timing wheel has a corresponding set of holes for receiving therein the projections when the detecting wheels and timing wheels are angularly aligned with respect to each other. A biasing spring urges the detection shaft in one direction to force the detecting wheels against their associated timing wheels so that when the projections and holes on each set of wheels are in alignment, the biasing spring will force the detection shaft in one direction causing the projections to slide into their respective holes. The movement of the detection shaft thus provides an output indicating that the reference time set in the timer coincides with the actual time displayed by the time-indicating wheels.

6 Claims, 6 Drawing Figures TIME-DETECTING SYSTEM FOR A DIGITAL INTERVAL TIMER The present invention relates generally to a timedetecting system and more particularly to a timedetecting system for a digital interval timer.

In conventional digital interval timers, a set of timeindicating wheels are mounted on a common shaft and contain time indicia for displaying the time in digital form. A single detecting wheel and a single reference wheel are also mounted on the common shaft and such a timer is shown in FIG. 2. The reference wheel is limited in size and therefore the reference time set into the timer is limited to an accuracy of about ten minutes and the accuracy of the actual time detection is in the order of a few minutes. Thus, the conventional timers are disadvantageous since the reference time cannot be accurately set into the timer and consequently the detection accuracy of the timer is severely limited.

It is therefore a primary object of the present invention to provide a time-detecting system for a digital interval timer which enables the reference time to be set into the timer to an accuracy of one minute or less and to provide a time detection accuracy of the order of a few seconds.

It is a further object of the present invention to provide a time-detecting system for a digital interval timer wherein the accuracy of time detection is completely independent of the size of the reference timing wheels.

It is yet another object of the present invention to provide a time-detecting system for a digital interval timer wherein the reference time is set in the timer by means of a plurality of reference timing wheels.

The above and other objects of the present invention are carried out mounting a plurality of detecting wheels for rotation on a common detection shaft which also contains thereon the time-indicating timing wheels.

wheel and contains a set of projections which align with .a. corresponding set of holes provided in its associated timing wheel when the detecting wheels and timing wheels are in a predetermined angular relationship with respect to each other. A biasing spring biases the detection shaft in a direction to force each detecting wheel against its associated timing wheel so that when all of the detecting wheels and timing wheels are in angular alignment at the same time, the biasing spring will axially displace the detection shaft causing the projections to enter into their corresponding holes. A plurality of reference wheels are mounted adjacent respective ones of the detecting wheels and a gear train interconnects each reference wheel with its associated detecting wheel so that the detecting wheels may be individually set in a position to detect a reference time set into the timer by the reference wheels.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the present invention comprises the combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth insufficient detail to enable those persons skilled in the art to clearly understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings, wherein like reference characters denote like parts in the various views, and wherein:

FIG. I is a front view, partly in section, of a digital interval timer containing a time-detecting system according to the present invention;

FIG. 2 is a front view of a conventional timer employing a conventional time-detecting system;

FIG. 3 is a perspective view of certain components of the time-detecting system shown in FIG. 1;

FIG. 4 is a schematic view of one embodiment of an actuator device used in conjunction with the timedetecting system of the present invention;

FIG. 5 is a schematic view of another embodiment of an actuator device used in conjunction with the timedetecting system of the present invention; and,

FIG. 6 is a cross-section of the actuator device taking along the lines VIVI in FIG. 5.

One embodiment of a time-detecting system for a digital interval timer is shown in FIG. 1. The timer has a time-detecting system for indicating the actual time in a manner similar to a conventional digital clock and a reference time-indicating system for indicating the reference time which is to be detected by the timer.

The timer-indicating system includes a second timing wheel 3, a minute timing wheel 5, a IO-minute timing wheel 7 and an hour timing wheel 9.,Each of the timing wheels containsdigital time indicia around its periphery so that as the timing wheels rotate, the time is displayed in digital form through a window provided in the timer. Each of the timing wheels is mounted for rotation independently of the others on a detection shaft 10. The detection shaft 10 is monted for axial sliding movement for a very limited extent between a pair of support plates as described in more detail hereinafter.

The reference time-indicating system includes a minute reference timing wheel 15, a IO minute referencetiming wheel 17, and an hour reference timing wheel 19 each mounted for rotation independently of the others about a shaft 20. The reference timing wheels each contain digital time indicia so that the reference time to be set in the timer is displayed through a window in the timer.

The minute timing wheel 5 contains a set of ratchet teeth 5a arranged around the wheel. Similarly the 10- minute timing wheel 7 contains an array of ratchet teeth 7a and the hour timing wheel 9 contains an array of ratchet teeth 9a. In a similar manner, the reference timing wheels 15, 17 and T9 are each provided with an array of ratchet teeth 15a, 17a, and 19a respectively. All the ratchet teeth coact with pawls on a set of operating levers (not shown) which are manually actuated to selectively adjust the angular position of each timing wheel thereby enabling correction of the time displayed by the time-indicating timing wheels and the time displayed by the reference timing wheels. The coaction between the individual operating levers and the timing wheels does not constitute part of the present invention nor is such necessary for an understanding of the invention and reference is herein made to copending application Ser. No. 307,867 entitled TIME- SETTING DEVICE FOR SETTING TIMING WHEELS IN A DIGITAL INTERVAL TIMER filed.

tecting wheel 22, and an hour detecting wheel 23. The minute detecting wheel 21 is provided with a set of projections 21a and the timing wheel 5 has a corresponding set of openings 5b for each receiving therein one of the projections 21a when the detecting wheel is in angular alignment or in phase with the timing wheel 5. By such a construction, the detection wheel 21 can be displaced rightward along the detection shaft towards the timing wheel 5 whenever the detection wheel is angularly orientated relative to the timing wheel such a set of projections 21a align with the openings 5b. In a similar manner, the detecting wheel 22 has a set of projections 22a insertable into a corresponding set of openings 7a provided in the timing wheel 7 whenever the detection wheel 22 is in a predetermined angular orientation relative to the timing wheel 7. Likewise, the detection wheel 23 has a set of projections 23a insertable into corresponding openings 9b provided in the timing wheel 9 when the wheels are in angular alignment.

The detecting wheels 21, 22 and 23 are mounted for rotational movement about the detection shaft 10 and are each in sliding contact with its associated timing wheel. A set of stop rings 25 are affixed to the detection shaft 10 and function to limit the extent of axial movement of the detecting wheels in the leftward direction along the shaft. A biasing spring 26 biases the detection shaft 10 in a rightward direction so that each detecting wheel is urged against and in sliding contact with its associated timing wheel. By such an arrangement, the detection shaft 10 may be axially displaced in the rightward direction only when the projections on each detecting wheel concurrently align with the openings in each timing wheel whereupon the biasing spring 26 will move the detection shaft 10 in a rightward direction causing all of the projections to slide within the corresponding openings in the timing wheels. If only one or two of the detecting wheels are in angular alignment with their associated timing wheels, the detection shaft 10 cannot be displaced since the projections on the remaining detecting wheel abut against the side wall of its associated timing wheel thereby preventing axial displacement of the detection shaft. It is only when all three detecting wheels are simultaneously in angular alignment or in phase with their respective timing wheels that the detection shaft may be displaced.

The projections on each detecting wheel are angularly spaced around the wheel in non-equal intervals so that the projections will only align with the openings in the timing wheel when the two wheels are in a single angular position. The timing wheels may be rotated relative to the detecting wheels and the detecting wheels may be rotated relative to the timing wheels.

An intermediate gear 30 is rotatably mounted on the rotation shaft 10 and the gear 30 is splined to the minute detecting wheel 21 to permit the minute detecting wheel to move axially along the detection shaft 10 relative to the gear 30 while coupling together the two gears for angular rotation together as a unit. The type of splined connection is shown in more detail in FIG. 3 and the connection comprises a pair of projections 31a, 31b extending outwardly from the gear 30 and which are slidably received between a pair of projections 27a, 27b provided on the detecting wheel 21.

The intermediate gear 30 isin mesh with a minute setting gear 34 which is mounted for rotation on a shaft 35. The minute setting gear 34 is in meshing engagement with gear teeth 15b provided around the periphery of the minute reference wheel 15. The gear train comprising the minute reference wheel 15, the minute setting gear 34, the intermediate gear 30 and the minute detecting wheel 21 effects angular displacement of the detecting wheel 21 in response to angular displacement of the minute reference wheel 15. By such an arrangment, the minute reference wheel 15 may be selectively set into a desired position corresponding to the reference time to be detected by the timer and the movement of the minute reference wheel into its desired position effects synchronous movement of the minute detecting wheel 21 into a position such that the projections 21a will align with the openings 5b when the minute indicating wheel 5 is in a position wherein the time indicated by that wheel coincides with the time indicated by the minute reference wheel 15. In a somewhat similar manner, the 10-minute detecting wheel 22 is in mesh with a lO-minute setting gear 36 which is in mesh with gear teeth 17b provided around the periphery of the 10-minute reference wheel 17 and the hour detecting wheel 23 is in mesh with the hour setting gear 37. Thus the lO-minute detecting wheel 22 and the hour detecting wheel 23 may be angularly displaced to desired positions in response to angular displacement of the lO-minute reference wheel 17 and the hour reference wheel 19.

A conventional drive system is employed for rotationally driving the timing wheels 3, 5, 7 and 9 in timed relationship with respect to each other to form a digital clock. The drive system includes a rotationally driven shaft 40 and a set of drive gears connected to the shaft and engaging with the timing wheels to rotationally drive them in response to rotational movement of the shaft 40. A drive gear 41 is connected to the shaft 40 and engages with gear teeth on the second indicating wheel 3 for rotationally driving the wheel 3 at a speed of one revolution per minute. A drive gear 42 is connected on the shaft 40 and engages with toothed sectors on both the wheel 3 and the wheel 5 for angularly driving the wheel 5 a predetermined angular increment in response to one revolution of the wheel 3. For example, the minute indicating wheel 5 could move through an angle of 36 per revolution of the wheel 3. Another drive gear 43 is mounted on the shaft 40 and engages with gear sectors provided on the wheel 5 and on the IO-minute indicating wheel 7 and the gear 43 rotationally drives the wheel 7 a predetermined angular increment in response to one revolution of the wheel 5. For example, the wheel 7 could move through an angle of 30 in response to one revolution of the wheel 5. In a like manner a drive gear 44 is connected to shaft 40 and meshes with gear sectors on the wheel 7 and on the hour indicating wheel 9 to angularly drive the wheel 9 through a predetermined angular increment in response to one revolution of the wheel 7 and in the embodiment illustrated, the wheel 9 is displaced through an angle of 60 in response to one revolution of the wheel 7. Thus, the drive system rotates each of the time-indicating wheels at different rates and in timed relationship with respect to each other so that the wheels function as a digital clock and display the time in digital form.

The operation of the time-detecting system will now be described with reference to FIG. 1. FIG. 1 shows the positions of the various components when the time set in the reference time-indicating system differs from the actual time in the time-indicating system. More particularly, the reference time set by the minute reference wheel I5 does not coincide with the time displayed by the minute indicating wheel 5 and therefore the minute detecting wheel 211 is not in angular alignment with the wheel 5. Consequently, the projections M on the detecting wheel 2ll are not in alignment with the openings 5b provided in the minute indicating wheel 5 and therefore the detection shaft I0 is maintained in its leftward position. At this instant, the time set by the -minute reference wheel I7 and the hour reference wheel I9 coincides with the time displayed by the 10-minute indicating wheel 7 and the hour indicating wheel 7 and the hour indicating wheel 9 and therefore the detecting wheels 22 and 23 are in angular alignment with their respective timing wheels.

When the drive system drives the minute indicating wheel 5 into a position wherein the holes 5b respectively align with the projections 21a, all of the detecting wheels will be in alignment with their respective timing wheels and at that instant, the biasing spring 26 will urge the detection shaft 10 in a rightward direction whereupon each detecting wheel is moved rightwardly into engagement with its corresponding timing wheel.

When it is desired to change the reference time which is to be detected by the timer, the reference wheels are individually and angularly displaced about the shaft to set the desired reference time in the timer. The angular displacement of the reference wheels is effected by operating levers (not shown) which coacts with the ratchet teeth llSa, 117a, ll9a on the reference wheels and such is disclosed in detail in the aforementioned copending application entitled TIME-SETTING DEVICE FOR SETTING TIMING WHEELS IN A DIGITAL INTERVAL TIMER. As each reference wheel is moved into its desired position, the corresponding detecting wheel is likewise moved into the proper detecting position through the time setting gears 34, 36 and 37. During assembly of the timer, the phase relationships between the timing wheels 5, 7 and II and their associated reference wheels 15, 17 and I9 is carefully set so that the projections on the detecting wheels are in alignment with their corresponding openings in the timing wheels when the reference time coincides with the actual time and this phase relationship is maintained throughout the operation of the device.

Assuming that it is desired to set a new hour reference time, the hour reference wheel 19 is angularly displaced into the desired position and during movement of the reference wheel W, the motion thereof is transmitted through the gear'37 to the detecting wheel 23 to accordingly position the detecting wheel in the proper position. Then when the hour indicating wheel 9 advances into the position wherein the time indicia displayed by the wheel 9 corresponds to the time indicia displayed by the reference wheel 19, the projections 23a will be in alignment with the openings 9b.

The time-detecting system of the present invention coacts with an actuator device for controlling the actuation of a switch housed within the timer. One embodiment of an actuator device is shown in FIG. 6 and comprises a baseplate 50 having slidably mounted thereon a manually displaceable setting member 52. The setting member has a projecting portion 53 engages with a flexible contact member of a switch 55 to maintain the contact member in spaced-apart relationship from a stationary contact member thereby maintaining the switch 55 in an open state. During displacement of the setting member 52 to the position shown in FIG. 4, the locking lever 56 is moved by a lever 62 into a locking position wherein same engages with a pin 57 extending outwardly from the base plate 50. The locking lever 56 is mounted for pivotal movement about a pin 56 and the lever 56 is also mounted on the pin 56 for tilting movement away from the base plate 50 to enable the locking lever to disengage from the fixed pin 57. A set of biasing springs 59, coact with a pivotal lever 62 to displace the setting member 52 in a leftward direction in response to disengagement of the locking lever 56 from the pin 57 and as the setting member moves leftward, the flexible contact member engages with the stationary contact member thereby placing the switch 55 in a closed state.

The actuator device per se and the mode of operation of the actuator device does not constitute part of the present invention and reference is herein made to copending application Ser. No. 307,866 entitled ACTU- ATOlR DEVICE FOR USE WITH AN INTERVAL TIMER for a detailed explanation of the actuator device. All that is necessary for an understanding of the present invention is that the detection shaft I0 coacts with the actuator device to release the locking lever 56 whereupon the output device 55 is placed in a closed stated. The switch 55 may be connected to an electric appliance such as a radio, television set, etc., so that the electric appliance will be turned on at a reference time selected by the timer and detected by the timedetecting system of the present invention.

A variation of the actuator device shown in FIG. 4 is shown in FIGS. 5 and 6 and in this embodiment, a lever is pivotally mounted at one end to the pin 58 at the other end of the lever is slidably mounted within a slot provided in the base plate 50. The lever 65 has an arcuate portion 65a and a planar portion 65b adjacent the arcuate portion and the portion 65b engages with the end tip of the detection shaft 10 when the lever 65 is in one position and disengages from the detection shaft when the lever is moved to another position in response to setting of the actuator device. As seen in FIG. 5, the lever 65 moves in an upward direction in response to counterclockwise pivotal movement of the lever 62 and such occurs during rightward movement of the setting member 52 during setting of the actuator device. In the position shown in FIGS. 5 and 6, the lever 65 is maintained out of engagement with the detection shaft 10 thereby allowing the detection shaft to move axially towards the locking lever 56 to disengage same from the pin 57.

When the actuator device is in its unlocked state and the setting member 52 is in its leftmost position, the lever 62 is biased in a clockwise direction about the pin 61 so that the planar portion 65b of the lever 65 overlies the end of the direction shaft 10 and urges the shaft against the force exerted by the biasing spring 26 shown in FIG. ll. Thus, the detecting wheels and the timing wheels are free of the biasing force exerted by the spring 26 so that they may move relative to each other in a smooth manner. During setting of the actuator device, the lever 65 is displaced leftwardly as viewed in FIG. 6 to move the planar portion 65a away from the detection shaft I0 whereupon the biasing spring 26 will be effective to urge the detection shaft in a rightward direction at the moment the reference time is detected by the time-detecting system.

It is to be understood that the invention may be carried out by reversing the position of the projections and holes provided on the detection wheels and the timing wheels. For example, the projections may extend outwardly from the timing wheels and the holes may be provided in the detecting wheels instead of the arrangement shown in FIG. 1. It is also possible to provide a second detecting wheel and a second reference wheel for detecting the position of the second indicating wheel 3 if such is desired. In a similar manner, suitable reference wheels and detecting wheels may be provided to detect the day of the week or the date of the year. Obvious changes and modifications may be made to the time-detecting system described above and the present invention is intended to cover all such obvious changes falling within the scope and spirit of the invention as defined in the appended claims.

What we claim is:

1. In a digital timer: an axially displaceable detection shaft; a plurality of rotationally driven timing wheels each mounted for rotation independently of the others on said detection shaft and each containing digital time indicia for collectively displaying the time in digital form; a plurality of reference wheels each mounted for rotation independently of the others and each containing digital time indicia for collectively displaying a reference time to be detected; and time-detecting means for detecting when the time displayed by said timing wheels coincides with the reference time displayed by said reference wheels and effecting axial displacement of said detection shaft in response to detection of said reference time.

2. A digital timer according to claim 1; wherein said time-detecting means includes a plurality of detecting wheels each mounted for rotation independently of the others on said detection shaft and each positioned adjacent one of said timing wheels, means on each detecting wheel cooperative with a complementary means on each adjacent timing wheel for preventing movement of said detecting wheels towards said timing wheels and thereby preventing axial displacement of said detection shaft until said reference time is detected, and biasing means biasing said detection shaft in one axial direction and effecting axial displacement thereof in said one direction in response to detection of said reference time.

3. A digital timer according to claim 2; wherein said means on each detecting wheel comprises a set of projections extending outwardly therefrom towards its adjacent timing wheel, and said complementary means on each adjacent timing wheel comprises means defining a set of openings thereon dimensioned to receive said set of projections whenever the time displayed by that timing wheel coincides with the time displayed by the corresponding reference wheel.

4. A digital timer according to claim 3; including means for independently adjusting the angular position of each detecting wheel in response to and in synchronization with the change in position of its corresponding reference wheel.

5. A digital timer according to claim 4; wherein said last-mentioned means comprises a gear train interconnecting each detecting wheel and its corresponding reference wheel.

6. A digital timer according to claim 2; wherein said biasing means comprises a biasing spring continuously urging said detection shaft in said one direction. 

1. In a digital timer: an axially displaceable detection shaft; a plurality of rotationally driven timing wheels each mounted for rotation independently of the others on said detection shaft and each containing digital time indicia for collectively displaying the time in digital form; a plurality of reference wheels each mounted for rotation independently of the others and each containing digital time indicia for collectively displaying a reference time to be detected; and time-detecting means for detecting when the time displayed by said timing wheels coincides with the reference time displayed by said reference wheels and effecting axial displacement of said detection shaft in response to detection of said reference time.
 2. A digital timer according to claim 1; wherein said time-detecting means includes a plurality of detecting wheels each mounted for rotation independently of the others on said detection shaft and each positioned adjacent one of said timing wheels, means on each detecting wheel cooperative with a complementary means on each adjacent timing wheel for preventing movement of said detecting wheels towards said timing wheels and thereby preventing axial displacement of said detection shaft until said reference time is detected, and biasing means biasing said detection shaft in one axial direction and effecting axial displacement thereof in said one direction in response to detection of said reference time.
 3. A digital timer according to claim 2; wherein said means on each detecting wheel comprises a set of projections extending outwardly therefrom towards its adjacent timing wheel, and said complementary means on each adjacent timing wheel comprises means defining a set of openings thereon dimensioned to receive said set of projections whenever the time displayed by that timing wheel coincides with the time displayed by the corresponding reference wheel.
 4. A digital timer according to claim 3; including means for independently adjusting the angular position of each detecting wheel in response to and in synchronization with the change in position of its corresponding reference wheel.
 5. A digital timer according to claim 4; wherein said last-mentioned means comprises a gear train interconnecting each detecting wheel and its corresponding reference wheel.
 6. A digital timer according to claim 2; wherein said biasing means comprises a biasing spring continuously urging said detection shaft in said one direction. 